When Lexie reaches the fringes of Soho, she stops. She feels for Innes Kent's note and business card, which she has kept in her bag since the day she met him. She doesn't need to look but she does anyway. Editor, it reads, Elsewhere Magazine, Bayton Street, Soho, London W1.

Mrs Collins had been shocked that morning when Lexie came upon her on the stairs and let slip she was going to Soho later in the day. Lexie had asked her why. 'Soho?' Mrs Collins replied. 'It's full of bohemians and inebriates.' Then she narrowed her eyes. 'You,' she said, and pointed at Lexie, 'you're always asking why, aren't you? Curiosity killed the cat.'

Lexie laughed. 'But I'm not a cat, Mrs Collins,' she said, and ran the rest of the way down the stairs.

Lexie looks up the street that on her map is marked as Moor Street. It seems quiet for a place full of inebriates. There is one car parked at the side of the road; a man is standing in a doorway, reading a newspaper; there is an awning half closed above a shop; in a third-storey window a woman is leaning out to water some flowers in a window box.

Lexie takes one step into Soho, then another, and another. She has the odd sensation that she is motionless, that the pavement is moving under her and that the houses and buildings and street signs are reeling past. Her shoes make a clear toc-toc sound as she walks. The man with the newspaper looks up. The woman in the window pauses with her watering.

She walks past a shop with cheeses, big as wheels, stacked in the window. A man in a white apron is standing on the doorstep, shouting something in a foreign language to a woman with a baby across the street. He grins and nods at Lexie as she passes and she smiles back. Around the corner is a coffee-house, with men standing on the pavement outside, talking in a different language. They part, just enough to let her through, and one of them says something to her but she doesn't look back.

The buildings are crowded together, dark brick, the roads narrow. The gutters run and ripple with the earlier rain. Around another corner, and another, past a Chinese grocer's, where a woman is stacking pitted yellow fruits into a pyramid, past a doorway where two African men are sitting on chairs, laughing. A gaggle of sailors in blue and white uniforms are walking down the middle of the road, singing in staggered, off-key unison; a delivery boy on a bicycle has to swerve to avoid them and he turns to shout something over his shoulder. Two or three of the sailors seem to take exception and dart after him but the delivery boy pedals hard and disappears.

Lexie watches all this. She takes it all in. Everything she sees seems freighted with significance: the fluttering ribbon on one of the sailor's hats, a marmalade cat washing itself on a window, the billow of steam that gathers in the air outside that bakery, the chalked words – Italian? Portuguese? – on a board outside a shop, the strains of music, interspersed with laughter, that wreathe up from a grating in the pavement, the fur-collared coat and gold-clasped bag of a woman passing on the opposite pavement. Lexie drinks it in, every detail, with a feeling between panic and euphoria: this is perfect, this is all perfect, it couldn't be more perfect, but what if she can't remember it all, what if even the tiniest element were to slip from her?

She arrives rather suddenly outside the address in Bayton Street. It is a building squeezed between two taller buildings, with a symmetrical arrangement of sash windows and steps up to the door. Paint is peeling in curls off the sills and gutters. A pane on the second floor is missing.

Beyond the windows on the ground floor, Lexie can see a great number of people. Two men are peering at something they are holding up to the light; there is a woman on the phone, nodding, writing. Another woman is measuring a piece of paper with a ruler, talking over her shoulder to a man at the desk behind hers. In a corner of the room a group of people are bunched together, crowding round to look at some pages pinned to the wall. And there, next to the men holding something up to the light, jacketless, with his sleeves rolled up, is Innes.